Hydraulic motor



Feb. 4, 1964 E. GILREATH HYDRAULIC MOTOR 3 Sheets-Sheet 1 Filed Dec. 1,1960 INVENTOR. lav/aye zfe GMreorfi ATTORNEY Feb. 4, 1964 E. GlLREATHHYDRAULIC MOTOR 3 Sheets-Sheet 2 Filed Dec. 1, 1960 wzz sf United StatesPatent 3,120,154 HYDRAULIC MGTGR Lafayette E. Gilreath, 7623 Arnim St.,Houston, Tex. Filed Dec. 1, 1960, Ser. No. 73,026 2 Claims. (Cl. 91-135)This invention ralates to hydraulically powered motors and moreparticularly to a hydraulic motor of the vane type.

The invention has for an important object the provision of ahydraulicmotor of the vane type embodying means for preventing the leakage ofhydraulic fluid past the vanes during the operation of the motor.Another object of the invention is to provide a hydraulic motor having arotor and a stator within which the rotor is rotatably mounted andincluding vanes movably mounted on the rotor for radial movement incontact with the stator and means for equalizing the hydraulic pressureexerted on the vanes during the idling movement of the vanes and forcausing the exertion of a greater hydraulic pressure radially outwardlyon the vanes than the pressure exerted radially inwardly thereon duringthe power transmitting movement of the vanes.

A further object of the. invention is the provision of a hydraulic motorof the vane type whose directionof rotation may be reversed by reversalof the direction of fiow of fluid through the motor.

Another object of the invention is to provide a hydraulic motor designedespecially for operation at widely varying speeds and fluid pressureconditions md having means for making use of the pressure of theoperating fluid for preventing loss of power due to leakage of fluidbetween the rotor and stator 01 the motor.

A further object of the invention is the provision of a hydraulic motorof the type mentioned, which is of simple design and ruggedconstruction, having few parts, which may be economically manufactured,and in which the parts are easily replaced for purposes of maintenanceand repair.

The above and other important objects and advantages of the inventionmaybest be understood from the following deta led description, constitutinga specification of the same, when considered in conjunction with theannexed drawings, wherein:

FIGURE 1 is a side elevational view, on a reduced scale, illustrating apreferred embodiment of the motor of the invention;

FIGURE 2 is a cross-sectional View, taken along the line 22 of FIGURE 1,looking in the direction indicated by the arrows, and showing details ofstructure of one part of the stator of the motor;

FIGURE 3 is a cross-sectional View, taken along the line 3-3 of FIGURE1, looking in the direction indicated by the arrows and showing detailsof construction of the rotor of the motor and relationship thereto ofthe fluid passageways of one part of the stator;

FIGURE 4 is a view, similar to that of FIGURE 3, taken along the line 44of FIGURE 1 showing the relationship of the fluid passageways of theanother part of the stator of the motor tothe rotor thereof;

FIGURE 5 is a cross-sectional view taken along the line 55 of FIGURE 1,looking in the direction indicated by the arrows, showing details of theinternal structure of one of the stator parts of the motor;

FIGURE 6 is a cross-sectional view, on a greatly enlarged scale, takenalong the line 66 of FIGURE 3, looking in the direction of the arrows,showing details of structure of the parts and the fluid pressuremechanism by which the vanes of the motor are operated; and

FIGURE 7 is a perspective View of one of the vanes of the motor asillustratedin FIGURE 6, removed from the surrounding structure of themotor.

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Referring now to the drawings in greater detail, the motor of theinvention has a stator or housing made up of two outer, identical,disk-like parts 10 and 12, and a central, ring-like part 14 positionedbetween the parts 1%) and 12 to form a somewhat oval shaped, internalcavity, generally indicated at 16 in which the rotor 18 is rotatablymounted. Each of the parts 1% i2 and 18 has a central openingtherethrough, through which a drive shaft 2% is extended, which issplined or otherwise secured to the. rotor, as indicated at 22' inFIGURE 3, for rotation therewith, and which is freely rotatable relativeto the stator.

The parts 19, 12 and 14 are secured together, as by means of bolts 24extending through suitable openings in the parts, suitable means, suchas the gaskets 26 and 28 being positioned between the parts to. formfluid tight seals with the same. T he gaskets 26 and 28 are providedwith elongated slots which register with the slots 36, 40 and. 42. whenthe motor is assembled.

The parts It! and 12 are of identical construction, each having apassageway 38 which is internally threaded at its outer end for theconnection thereto of a fluid pressure supply pipe 32' or a dischargepipe 34 through which fluid under pressure is supplied to or conductedaway from the interior of the stator. Elongated arcuate slots 36 and 38are provided in each stator part It? and 12 in communication with thepassageway 39 at positions to allow the inflow of fluid to the statorand the outflow of fluid therefrom at suitable locations in a manner tobe hereinafter pointed out. Each of the stator parts Iii and 12 also hasadditional elongated, arcuate slots 4i and 42 therein which are incommunication with the passageway 36 through branch passageways 4d, andwhich are for purposes to be hereinafter explained.

The stator parts ill and 12 may be provided with external, centrallylocated recesses 46 for the reception of suitable bearings, such asthose indicated at 43', surrounding the drive shaft 2% to permit theshaft to rotate freely in the stator.

The rotor 13 is of circular shape to fit within and rotate in the cavity16, to provide oppositely disposed, arcuate, pressure chambers 52 withinthe stator exteriorly of the rotor. The rotor is also of a thickness toclosely fit between the gaskets 25 and 2-8 in sealing contact therewith,so that the rotor may rota-te within the stator without leakage of thepressure fluid from the chambers 52 past the rotor.

The rotor is provided with a plurality of peripherally spaced, radiallyextending, external, cyiiudrical recesses 56, whose inner ends areclosed and whose outer ends open outwardly inrto external slots 58 ofrectangular shape in cross-section. Movable vane elements, such as thatgenerally designated 60, in FIGURE 7 are provided for the rotor 18, eachof which has a cylindrical piston portion 62 sl-idahl-y fittedinto oneof the recesses 56, and a vane portion 64 or" rectangular shape incross-section which is sliidably disposed in the corresponding one ofthe external slots 53.. The portion 62is provided with an end recess 5'6in its inner end, as seen in FIGURE 6,, in which a coil spring 68 ispositioned which engages the piston and the bottom of the recess 56 toyieldingly urge the vane radially outwardly into contact with thesurrounding wall of the stator part 14. Each vane element carries aroller 76 positioned for rolling contact with the surrounding wall ofthe stator cavity 16. The vane portion 64 of each vane element haspassageways 72 and 74 therelthrough each of which is provided with avalve 76 which functions to allow the flow of fluid from the cavity 16inwardly through the vane portion 64, but which prevents the flow offluid through the vane portion into the cavity 16.

The combined areas of the vane portion 64, and cylindrical portion 62which is exposed to fluid pressure in the recess 56 and the slot 58,tending to urge the vane radially outwardly into engagement with thesurrounding wall of the cavity 16, is greater than the area of the vanewhich is exposed to pressure in the chamber 52 tending to rotate therotor. Thus, one side face of the vane in the chamber 52 be exposed tothe pressure of fluid entering the chamber through the inlet pipe 32,and the passageway 39 and elongated slots 36 and 38 associated therewithto apply a force to the vane tending to rotate the rotor. The durationof the application of rotative force to the vane is determined by thelengths of the slots 36 and 38. All of the rollers 70 are held inrolling contact with the surrounding wall of the cavity 16, duringrotation of the rotor, by the coil springs 68, as each of the vanesreaches a position to allow the inlet pressure of fluid to enter thechamber 52 through one of the slots 36, 38 to apply pressure to one sideof the vane to apply 7 a relative force to the rotor, both of the slots40 and 42 will then be in communication with the inlet pipe to allowfluid :under pressure to enter the recess 56, beneath the piston portion62 and the slot 58 beneath the vane pressure 64 to apply a pressure tothe vane tending to urge the vane radially outwardly, which is greaterthan the pressure exerted on the side surface of the vane tending torotate the rotor, whereby the vane will be held against radial inwardmovement away from the surrounding wall of the chamber 52, toeffectively prevent leakage of fluid past the vane during the powertransmitting portion of its movement in the ch amber.

As each vane moves past the slot 36 or 38 in the chamber'52, the inletpressure applied thereto will be cut off, and the next vane will be inposition for the application thereto of the inlet pressure to apply arotative force to the rotor.

The inlet pressure applied to the vane in the recess 56 and slot 58,tending to urge the vane radially outwardly is applied only during thetime that the vane is moving past the slots 40 and 42, and when the vanehas moved past these slots, pressure in the chamber 52 may flow throughpassageways 72 and 74 into the slot 58, beneath the vane portion 64, toequalize the radial inward and outward pressures exerted on the vane.The vane is then urged radially outwardly only by the pressure of thespring 68. Thus, during the time that the rotative force is exerted onthe vane, the pressure exerted radially outwardly on the vane willexceed the pressure exerted thereon in the direction of movement of thevane, to hold the vane in sealing contact with the stator to preventleakage of fluid past the vane during the application of rotative forceto the vane.

As soon as each vane passes one of the inlet slots 36 and 38, thepreceding vane will have moved to a position to permit the outflow offluid through one of the discharge slots, to exhaust fluid from thechamber 52.

It will thus be apparent that the outward pressure exerted on the vaneswill be in excess of the inward pressure exerted thereon only during thetime that pressure is being applied to the vane tending to rotate therotor, and during idling movement of the vanes, the vanes are urgedoutwardly only by the pressure of the coil springs 68. Thus, the forcerequired to hold the vanes in their retracted positions during idlingmovement of the vanes is reduced to a minimum, while at the same timethe vanes will be securely held in sealing contact with the statorduring the power transmitting portions of their movement.

Because of the greatly improved sealing etieot accomplished by theapplication of an outward force to the vanes in excess of the forcetending to rotate the rotor during the power transmitting movement ofthe vanes, it

,will be apparent that the motor of the invention is particularlysuitable for use at relatively low speed, without loss due to leakage,and that the motor may be effioiently operated throughout a Wide rangeof speeds.

It will, of course, be understood that the motor of the invention may beoperated from any suitable source of fluid under pressure, such as anhydraulic pump of usual design, by which hydraulic fluid may becirculated through the motor, under the control of the usual valvemechanism.

It will also be apparent that because of the symmetrical arrangement ofthe inlet and outlet passageways of the motor, the motor may be operatedin either direction by merely reversing the direction of flow of thehydraulic fluid therethro-ugh. 1

It will thus be seen that the invention, constructed and arranged asdescribed above describes an hydraulic motor of simple design and ruggedconstruction having few parts, a

which is eflicient in operation and in which the parts may be easilyreplaced for purposes of maintenance and repair.

The invention is disclosed herein in connection with a certain specificembodiment of the same, but it will be understood that is intended byway of illustration only and that various changes may be made in theconstruction and arrangement of the parts within the spirit of theinvention and the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimedas new and desired to secure by Letters Patent is:

1. In a hydraulic motor a hollow stator having an internal peripheralwall, a rotor rotatably positioned in the stator and having an externalperipheral wall located in radially inwardly spaced relation to saidinternal wall, peripherally spaced, radially extending, externalrecesses in the rotor, a vane movably disposed in each recess andextending radially in sealing contact with the rotor and stator to forma seal between said walls, means for ad mitting fluid under pressureinto the stator between said walls at one location and for allowing theoutflow of fluid from the stator between said walls at another locationto apply a force to one side of each of said vanes during rotation ofthe rotor in a direction to cause the rotor to rotate, each of saidvanes having a passageway opening into the interior of the stator oneach side of the vane and leading to the interior of the recess radiallyinwardly of the vane, 21 valve seat in each passageway through whichfluid may flow through the passageway and valve means movably disposedin each passageway for movement to one position to close the seatagainst the outflow of fluid through the passageway and to anotherposition to open the seat.

2. In a hydraulic motor a hollow stator havingan internal peripheralwall, a rotor rotatably positioned in the stator and having an externalperipheral wall located in radially inwardly spaced relation to saidinternal wall, peripherally spaced, radially extending, externalrecesses in the rotor, a vane movably disposed in each recess andextending radially outwardly from the stator in sealing contact with therotor and stator and with said internal wall to form a seal between thewalls, each of said vanes having radially spaced, radially inwardlyfacing surfaces in the recess, inlet means for admitting fluid underpressure into the stator between said walls at one location and outletmeans for allowing an outflow of fluid from the stator between saidwalls at another location to apply a force to one side of each vane whenthe vane is between the inlet and outlet means to cause the rotor torotate, each of said vanes having a passageway whose inner end opensinto the recess through one of said faces and whose outer end opens intothe statorbetween said walls at one side of the vane and anotherpassageway whose inner end opens into the recess through the other ofsaid faces and whose outer end opens into the stator between said wallsat the other side of the vane, a valve for controlling the flow of fluidthrough each passageway to allow an inflow of fluid into the recess andto prevent the outflow of fluid therefrom, and means for admitting fluidunder pressure from said inlet means into the recess radially inwardlyof said faces during the application of such force to the vane.

References Cited in the file of this patent UNITED STATES PATENTSBsekman Jan. 26, 1875 Keavy Aug. 20, 1889 Craig Feb. 6, 1900 CharlesAug. 5, 1902 Dunn Mar. 24, 1903 Walters July 14, 1903 Walters Aug. 4,1903 Augustine Dec. 6, 1904 Lofton Nov. 14, 1905 McLean Feb. 13, 1906Kaiser Oct. 30, 1905 Austin July 2, 1907 Tippett et a1 Out. 29, 1907Nichols *Feb. 7, 1911 Rasmussen Jan. 7, 1919 6 Lambert May 11, 1920Ensign May 26, 1925 Hott June: 16, 1931 Norling July 4, 1933 Ernst et a1Nov. 2, 1943 Kay Nov. 30, 1943 Rosen Ian. 15, 1946 Ferris Mar. 24, 1953Welcn Nov. 10, 1953 Williams Jan. 10, 1956 Adams Jan. 15, 1957 StewartOct. 8, 1957 Rystrorn Apr. 17, 1962 FOREIGN PATENTS Germany Dec. 1, 1923Germany Jan. 20, 1933

2. IN A HYDRAULIC MOTOR A HOLLOW STATOR HAVING AN INTERNAL PERIPHERALWALL, A ROTOR ROTATABLY POSITIONED IN THE STATOR AND HAVING AN EXTERNALPERIPHERAL WALL LOCATED IN RADIALLY INWARDLY SPACED RELATION TO SAIDINTERNAL WALL, PERIPHERALLY SPACED, RADIALLY EXTENDING, EXTERNALRECESSES IN THE ROTOR, A VANE MOVABLY DISPOSED IN EACH RECESS ANDEXTENDING RADIALLY OUTWARDLY FROM THE STATOR IN SEALING CONTACT WITH THEROTOR AND STATOR AND WITH SAID INTERNAL WALL TO FORM A SEAL BETWEEN THEWALLS, EACH OF SAID VANES HAVING RADIALLY SPACED, RADIALLY INWARDLYFACING SURFACES IN THE RECESS, INLET MEANS FOR ADMITTING FLUID UNDERPRESSURE INTO THE STATOR BETWEEN SAID WALLS AT ONE LOCATION AND OUTLETMEANS FOR ALLOWING AN OUTFLOW OF FLUID FROM THE STATOR BETWEEN SAIDWALLS AT ANOTHER LOCATION TO APPLY A FORCE TO ONE SIDE OF EACH VANE WHENTHE VANE IS BETWEEN THE INLET AND OUTLET MEANS TO CAUSE THE RATOR TOROTATE, EACH OF SAID VANES HAVING A PASSAGEWAY WHOSE INNER END OPENSINTO THE RECESS THROUGH ONE OF SAID FACES AND WHOSE OUTER END OPENS INTOTHE STATOR BETWEEN SAID WALLS AT ONE SIDE OF THE VANE AND ANOTHERPASSAGEWAY WHOSE INNER END OPENS INTO THE RECESS THROUGH THE OTHER OFSAID FACES AND WHOSE OUTER END OPENS INTO THE STATOR BETWEEN SAID WALLSAT THE SIDE OF THE VANE, A VALVE FOR CONTROLLING THE FLOW OF FLUIDTHROUGH EACH PASSAGEWAY TO ALLOW AN INFLOW OF FLUID INTO THE RECESS ANDTO PREVENT THE OUTFLOW OF FLUID THEREFROM, AND MEANS FOR ADMITTING FLUIDUNDER PRESSURE FROM SAID INLET MEANS INTO THE RECESS RADIALLY INWARDLYOF SAID FACES DURING THE APPLICATION OF SUCH FORCE TO THE VANE.